*{
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}
html,body{
    height: 100%;
    background-image: url("../image/wuziqi.png");
    background-repeat: no-repeat;
    background-position: center;
    background-size: cover;

}
.nav{
    height: 50px;
    background-color: black;
    color: white;
    line-height: 50px;
    padding-left: 20px;
}
.container{
    width: 100%;
    height: calc(100% - 50px);
    display: flex;
    align-items: center;
    justify-content: center;

}
